<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!-- 1.导入vue 开发环境版本，包含了有帮助的命令行警告 -->
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>

</head>
<body>
<!-- 2.定义标签 需要给一个标签添加 id -->
<div id="app">
    <span>{{message}}</span>

</div>
</body>
<!-- 3.创建vue实例 -->
<script type="text/javascript">
    var vm = new Vue({
        el: "#app",
        data: {
            message: 'hello',
        }
    })
</script>
</html>